Sleep Unit 4

No definitive answer Restorative Theory Adaptive Non-responding Theory Why do we sleep? No definitive answer Only theories: Restorative Theory Adaptive Non-responding Theory Combination

Circadian Rhythm Biological clock that governs how people function 1. Sequence of bodily changes (body temp, blood pressure, sleep and wake) 2. Usually operates on 24-hour day

Stages of Sleep Measured with EEG: 2 types (REM & NREM) 1. NREM (Non-rapid eye movement) Stage 1: Lightest Sleep; Alpha Waves- drowsy, slow eye movement, muscle activity stabilizes Stage 2: Theta Waves Stage 3 & 4: Delta waves – deepest sleep

Stages of Sleep… 2. REM (Rapid Eye Movement) Waves resemble wakefulness- CNS active Increased heart rate, blood pressure, O2 consumption Muscle activity suppressed

We pass through all stages in 90-minute cycle 4-6 cycles each night The Sleep Cycle We pass through all stages in 90-minute cycle 4-6 cycles each night Most slow wave sleep occurs early Most REM occurs in 2nd half of night

We All Need Sleep!!! Sleep range is from: - 4 to 10 hours - Average is 7.5 hours Effects of differing sleep duration may correlate with life expectancy Most people get less sleep than needed due to lifestyle

Do think that you often enter REM sleep? Table Talk Do think that you often enter REM sleep? Why? How many hours of sleep did you get last night? How many hours of sleep do you get on average?

Sleep Need… As long as 11 days Sleep Deprivation As long as 11 days After 2-3 days: micro sleep occurs (2-5 minute sleep) Selective sleep deprivation: deprived of REM

Sleep need changes with age Adult REM: 25%; over 60 declines to 15% Average drops from 7.5 hours to 6-7 hours as we age Sleep latency (time to fall asleep) increases Decline in stage 3 and 4 sleep

Sleep Disorders A. Insomnia: Difficulty in falling asleep, lasts 2-3 days Treatment by sleeping pills effective for only 2 weeks Learned/conditioned insomnia caused by bad sleeping habits Cognitive arousal (worry/anxiety) a cause Standard treatments: muscle relaxation techniques, hypnosis, sleep restriction therapy, psychotherapy

Sleep Disorders… B. Sleep Apnea Breathing interruption that occurs during sleep Occurs when air passages are blocked Do not automatically start breathing until they sit up and gasp for air May be linked to SIDS SIDS = Sudden Infant Death Syndrome

Sleep Disorders… C. Narcolepsy Suddenly fall asleep regardless of time or surroundings Fall into REM sleep and awaken feeling refreshed Treatment: drug therapy and frequent naps

How long can you last with sleep deprivation? Table Talk How long can you last with sleep deprivation? Do you or anyone you know suffer from a sleep disorder? What are you / they doing to treat or improve their condition?